I confirmed a couple weeks ago that I've got tinnitus and, as far as my memory tells me, have had it all my life. The missing piece was learning that tinnitus is not in the ear, but in the brain-- at the talk, the fellow pointed out that there are certain people who became so desperate to silence their tinnitus that they had their auditory nerve severed; but the result of this was that afterward, the only thing they could "hear" was the sound they wanted gone. Knowing this I finally was able to suspect, and then experimentally confirm (their experiment, not mine) that that's what this is.

What makes mine unusual-- so unusual, in fact, that beyond confirming it to exist their experimental procedure didn't know how to handle it-- is twofold. One is that it is a ringing in the back of my head, not in my ears. Another is that its volume is inversely proportional to the ambient sound; when I'm in a noisy room I can't hear it even when I try, but when I was in New Mexico at the top of a mountain, with fifty miles of nothing in every direction, the sound in my head was practically screaming. In their experiment, their computer kept playing sounds and asking me to compare them to what was in my head-- but it was impossible to make direct comparisons. The louder they played their sounds, the fainter my internal noise became.

Maybe that's one reason I like to listen to pleasant music; I don't like loud sounds, but I'll never have quiet either, so I might as well make the sound I'm subjected to something worth hearing.